| 1. |
- Beter, M., et al.
(författare)
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SproutAngio : an open-source bioimage informatics tool for quantitative analysis of sprouting angiogenesis and lumen space
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional image analyses are required to improve the understanding of the regulation of blood vessel formation and heterogeneity. Currently, quantitation of 3D endothelial structures or vessel branches is often based on 2D projections of the images losing their volumetric information. Here, we developed SproutAngio, a Python-based open-source tool, for fully automated 3D segmentation and analysis of endothelial lumen space and sprout morphology. To test the SproutAngio, we produced a publicly available in vitro fibrin bead assay dataset with a gradually increasing VEGF-A concentration (). We demonstrate that our automated segmentation and sprout morphology analysis, including sprout number, length, and nuclei number, outperform the widely used ImageJ plugin. We also show that SproutAngio allows a more detailed and automated analysis of the mouse retinal vasculature in comparison to the commonly used radial expansion measurement. In addition, we provide two novel methods for automated analysis of endothelial lumen space: (1) width measurement from tip, stalk and root segments of the sprouts and (2) paired nuclei distance analysis. We show that these automated methods provided important additional information on the endothelial cell organization in the sprouts. The pipelines and source code of SproutAngio are publicly available ().
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| 2. |
- Cottarelli, Azzurra, et al.
(författare)
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Fgfbp1 promotes blood-brain barrier development by regulating collagen IV deposition and maintaining Wnt/beta-catenin signaling
- 2020
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Ingår i: Development. - : COMPANY BIOLOGISTS LTD. - 0950-1991 .- 1477-9129. ; 147:16
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Tidskriftsartikel (refereegranskat)abstract
- Central nervous system (CNS) blood vessels contain a functional blood-brain barrier (BBB) that is necessary for neuronal survival and activity. Although Wnt/beta-catenin signaling is essential for BBB development, its downstream targets within the neurovasculature remain poorly understood. To identify targets of Wnt/beta-catenin signaling underlying BBB maturation, we performed a microarray analysis that identified Fgfbp1 as a novel Wnt/beta-catenin-regulated gene in mouse brain endothelial cells (mBECs). Fgfbp1 is expressed in the CNS endothelium and secreted into the vascular basement membrane during BBB formation. Endothelial genetic ablation of Fgfbp1 results in transient hypervascularization but delays BBB maturation in specific CNSregions, as evidenced by both upregulation of Plvap and increased tracer leakage across the neurovasculature due to reduced Wnt/beta-catenin activity. In addition, collagen IV deposition in the vascular basement membrane is reduced in mutant mice, leading to defective endothelial cell-pericyte interactions. Fgfbp1 is required cell-autonomously in mBECs to concentrate Wnt ligands near cell junctions and promote maturation of their barrier properties in vitro. Thus, Fgfbp1 is a crucial extracellular matrix protein during BBB maturation that regulates cell-cell interactions and Wnt/beta-catenin activity.
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| 3. |
- Georganaki, Maria, et al.
(författare)
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Tumor endothelial cell up-regulation of IDO1 is an immunosuppressive feed-back mechanism that reduces the response to CD40-stimulating immunotherapy
- 2020
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Ingår i: Oncoimmunology. - : TAYLOR & FRANCIS INC. - 2162-4011 .- 2162-402X. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- CD40-stimulating immunotherapy can elicit potent anti-tumor responses by activating dendritic cells and enhancing T-cell priming. Tumor vessels orchestrate T-cell recruitment during immune response, but the effect of CD40-stimulating immunotherapy on tumor endothelial cells has not been evaluated. Here, we have investigated how tumor endothelial cells transcriptionally respond to CD40-stimulating immunotherapy by isolating tumor endothelial cells from agonistic CD40 mAb- or isotype-treated mice bearing B16-F10 melanoma, and performing RNA-sequencing. Gene set enrichment analysis revealed that agonistic CD40 mAb therapy increased interferon (IFN)-related responses in tumor endothelial cells, including up-regulation of the immunosuppressive enzyme Indoleamine 2, 3-Dioxygenase 1 (IDO1). IDO1 was predominantly expressed in endothelial cells within the tumor microenvironment, and its expression in tumor endothelium was positively correlated to T-cell infiltration and to increased intratumoral expression of IFN gamma. In vitro, endothelial cells up-regulated IDO1 in response to T-cell-derived IFN gamma, but not in response to CD40-stimulation. Combining agonistic CD40 mAb therapy with the IDO1 inhibitor epacadostat delayed tumor growth in B16-F10 melanoma, associated with increased activation of tumor-infiltrating T-cells. Hereby, we show that the tumor endothelial cells up-regulate IDO1 upon CD40-stimulating immunotherapy in response to increased IFN gamma-secretion by T-cells, revealing a novel immunosuppressive feedback mechanism whereby tumor vessels limit T-cell activation.
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| 4. |
- Huang, Hua, 1986-, et al.
(författare)
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ELTD1-deletion reduces vascular abnormality and improves T-cell recruitment after PD-1 blockade in glioma.
- 2021
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Ingår i: Neuro-Oncology. - : Oxford University Press. - 1522-8517 .- 1523-5866. ; 24:3, s. 398-411
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Tumor vessels in glioma are molecularly and functionally abnormal, contributing to treatment resistance. Proteins differentially expressed in glioma vessels can change vessel phenotype and be targeted for therapy. ELTD1 (Adgrl4) is an orphan member of the adhesion G-protein-coupled receptor family upregulated in glioma vessels, and has been suggested as a potential therapeutic target. However, the role of ELTD1 in regulating vessel function in glioblastoma is poorly understood.METHODS: ELTD1 expression in human gliomas and its association with patient survival was determined using tissue microarrays and public databases. The role of ELTD1 in regulating tumor vessel phenotype was analyzed using orthotopic glioma models and ELTD1 -/- mice. Endothelial cells isolated from murine gliomas were transcriptionally profiled to determine differentially expressed genes and pathways. The consequence of ELTD1-deletion on glioma immunity was determined by treating tumor bearing mice with PD-1-blocking antibodies.RESULTS: ELTD1 levels were upregulated in human glioma vessels, increased with tumor malignancy, and were associated with poor patient survival. Progression of orthotopic gliomas was not affected by ELTD1-deletion, however, tumor vascular function was improved in ELTD1 -/- mice. Bioinformatic analysis of differentially expressed genes indicated increased inflammatory response and decreased proliferation in tumor endothelium in ELTD1 -/- mice. Consistent with an enhanced inflammatory response, ELTD1-deletion improved T-cell infiltration in GL261-bearing mice after PD-1 checkpoint blockade.CONCLUSION: Our data demonstrate that ELTD1 participates in inducing vascular dysfunction in glioma, and suggests that targeting of ELTD1 may normalize the vessels and improve the response to immunotherapy.
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| 5. |
- Huang, Hua, 1986-
(författare)
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Endothelial activation and inflammation in the tumor microenvironment
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tumors are composed not only of malignant cells, but also of various types of normal cells, including vascular cells and infiltrating immune cells, which drive tumor development and progression. The tumor vasculature is abnormal and dysfunctional due to sustained tumor angiogenesis driven by high levels of pro-angiogenic factors. Proteins differentially expressed in tumor vessels affect vascular function and the tumor microenvironment and may serve as targets for therapy. The tumor is also a site of sustained chronic inflammation. The recruitment and activation of inflammatory cells significantly influence tumor progression and regression. Targeting molecules regulating tumor angiogenesis and inflammation in the tumor microenvironment is therefore a promising strategy for the treatment of cancer. This thesis is aiming to understand and investigate the molecular regulation of these two processes in tumors.αB-crystallin is a heat shock protein previously proposed as a target for cancer therapy due to its role in increasing survival of tumor cells and enhancing tumor angiogenesis. In this thesis, we demonstrate a novel role of αB-crystallin in limiting expansion of CD11b+Gr1+ immature myeloid cells in pathological conditions, including tumor development. In addition, we show that αB-crystallin regulates leukocyte recruitment by promoting expression of adhesion molecules ICAM-1, VCAM-1 and E-selectin during TNF-α-induced endothelial activation. Therefore, targeting of αB-crystallin may influence tumor inflammation by regulating immature myeloid cell expansion and leukocyte recruitment.Abnormal, dysfunctional vessels are characteristic of glioblastomas, which are aggressive malignant brain tumors. We have identified the orphan G-protein coupled receptor ELTD1 as highly expressed in glioblastoma vessel and investigated its role in tumor angiogenesis. Interestingly, deficiency of ELTD1 was associated with increased growth of orthotopic GL261 glioma and T241 fibrosarcoma, but did not affect vessel density in any model. Further investigation is warranted to evaluate whether ELTD1 serves a suitable vascular target for glioblastoma treatment.Anti-angiogenic drugs targeting VEGF signaling is widely used in the clinic for various types of cancer. However, the influences of anti-angiogenic treatment on tumor inflammation have not been thoroughly investigated. We demonstrate that VEGF inhibits TNF-α-induced endothelial activation by repressing NF-κB activation and expression of chemokines involved in T-cell recruitment. Sunitinib, a small molecule kinase inhibitor targeting VEGF/VEGFR2 signaling increased expression of chemokines CXCL10, CXCL11, and enhanced T-lymphocyte infiltration into tumors. Our study suggests that anti-angiogenic therapy may improve immunotherapy by enhancing endothelial activation and facilitating immune cell infiltration into tumors.
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| 6. |
- van Hooren, Luuk, et al.
(författare)
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Agonistic CD40 therapy induces tertiary lymphoid structures but impairs responses to checkpoint blockade in glioma.
- 2021
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Ingår i: Nature communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Gliomas are brain tumors characterized by an immunosuppressive microenvironment. Immunostimulatory agonistic CD40 antibodies (αCD40) are in clinical development for solid tumors, but are yet to be evaluated for glioma. Here, we demonstrate that systemic delivery of αCD40 in preclinical glioma models induces the formation of tertiary lymphoid structures (TLS) in proximity of meningeal tissue. In treatment-naïve glioma patients, the presence of TLS correlates with increased T cell infiltration. However, systemic delivery of αCD40 induces hypofunctional T cells and impairs the response to immune checkpoint inhibitors in pre-clinical glioma models. This is associated with a systemic induction of suppressive CD11b+ B cells post-αCD40 treatment, which accumulate in the tumor microenvironment. Our work unveils the pleiotropic effects of αCD40 therapy in glioma and reveals that immunotherapies can modulate TLS formation in the brain, opening up for future opportunities to regulate the immune response.
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| 7. |
- Xie, Yuan, et al.
(författare)
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Key molecular alterations in endothelial cells in human glioblastoma uncovered through single-cell RNA sequencing
- 2021
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Ingår i: JCI Insight. - : American Society For Clinical Investigation. - 2379-3708. ; 6:15
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Tidskriftsartikel (refereegranskat)abstract
- Passage of systemically delivered pharmacological agents into the brain is largely blocked by the blood-brain-barrier (BBB), an organotypic specialization of brain endothelial cells (ECs). Tumor vessels in glioblastoma (GBM), the most common malignant brain tumor in humans, are abnormally permeable, but this phenotype is heterogeneous and may differ between the tumor's center and invasive front. Here, through single-cell RNA sequencing (scRNA-seq) of freshly isolated ECs from human glioblastoma and paired tumor peripheral tissues, we have constructed a molecular atlas of human brain ECs providing unprecedented molecular insight into the heterogeneity of the human BBB and its molecular alteration in glioblastoma. We identified 5 distinct EC phenotypes representing different states of EC activation and BBB impairment, and associated with different anatomical locations within and around the tumor. This unique data resource provides key information for designing rational therapeutic regimens and optimizing drug delivery.
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| 8. |
- Xie, Yuan, et al.
(författare)
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Wnt signaling regulates MFSD2A-dependent drug delivery through endothelial transcytosis in glioma
- 2023
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Ingår i: Neuro-Oncology. - : Oxford University Press. - 1522-8517 .- 1523-5866. ; 25:6, s. 1073-1084
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Tidskriftsartikel (refereegranskat)abstract
- Background: Systemic delivery of anti-tumor therapeutic agents to brain tumors is thwarted by the blood-brain barrier (BBB), an organotypic specialization of brain endothelial cells (ECs). A failure of pharmacological compounds to cross BBB is one culprit for the dismal prognosis of glioblastoma (GBM) patients. Identification of novel vascular targets to overcome the challenges posed by the BBB in tumors for GBM treatment is urgently needed.Methods: Temozolomide (TMZ) delivery was investigated in CT2A and PDGFB-driven RCAS/tv-a orthotopic glioma models. Transcriptome analysis was performed on ECs from murine gliomas. Mfsd2a deficient, Cav1 deficient, and Mfsd2a EC-specific inducible mice were developed to study the underlying molecular mechanisms.Results: We demonstrated that inhibiting Wnt signaling by LGK974 could increase TMZ delivery and sensitize glioma to chemotherapy in both murine glioma models. Transcriptome analysis of ECs from murine gliomas revealed that Wnt signaling inhibition enhanced vascular transcytosis as indicated by the upregulation of PLVAP and downregulation of MFSD2A. Mfsd2a deficiency in mice enhances TMZ delivery in tumors, whereas constitutive expression of Mfsd2a in ECs suppresses the enhanced TMZ delivery induced by Wnt pathway inhibition in murine glioma. In addition, Wnt signaling inhibition enhanced caveolin-1 (Cav1)-positive caveolae-mediated transcytosis in tumor ECs. Moreover, Wnt signaling inhibitor or Mfsd2a deficiency fails to enhance TMZ penetration in tumors from Cav1-deficient mice.Conclusions: These results demonstrated that Wnt signaling regulates MFSD2A-dependent TMZ delivery through a caveolae-mediated EC transcytosis pathway. Our findings identify Wnt signaling as a promising therapeutic target to improve drug delivery for GBM treatment.
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| 9. |
- Yau, Anthony C. Y., et al.
(författare)
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Inflammation and neutrophil extracellular traps in cerebral cavernous malformation
- 2022
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Ingår i: Cellular and Molecular Life Sciences (CMLS). - : Springer Nature. - 1420-682X .- 1420-9071. ; 79:4
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Tidskriftsartikel (refereegranskat)abstract
- Cerebral Cavernous Malformation (CCM) is a brain vascular disease with various neurological symptoms. In this study, we describe the inflammatory profile in CCM and show for the first time the formation of neutrophil extracellular traps (NETs) in rodents and humans with CCM. Through RNA-seq analysis of cerebellum endothelial cells from wild-type mice and mice with an endothelial cell-specific ablation of the Ccm3 gene (Ccm3(iECKO)), we show that endothelial cells from Ccm3(iECKO) mice have an increased expression of inflammation-related genes. These genes encode proinflammatory cytokines and chemokines, as well as adhesion molecules, which promote recruitment of inflammatory and immune cells. Similarly, immunoassays showed elevated levels of these cytokines and chemokines in the cerebellum of the Ccm3(iECKO) mice. Consistently, both flow cytometry and immunofluorescence analysis showed infiltration of different subsets of leukocytes into the CCM lesions. Neutrophils, which are known to fight against infection through different strategies, including the formation of NETs, represented the leukocyte subset within the most pronounced increase in CCM. Here, we detected elevated levels of NETs in the blood and the deposition of NETs in the cerebral cavernomas of Ccm3(iECKO) mice. Degradation of NETs by DNase I treatment improved the vascular barrier. The deposition of NETs in the cavernomas of patients with CCM confirms the clinical relevance of NETs in CCM.
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| 10. |
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